The present invention relates to a plasma display panel used in a television set.
As a conventional plasma display panel (PDP) having a matrix display, a face-discharge type PDP is known. A face-discharge type PDP having a three-electrode matrix display comprises a front substrate as a display side, and a rear substrate provided corresponding to the front substrate at a distance, thereby forming a discharge space there-between. The front substrate has a plurality of pairs of sustaining electrodes disposed thereon parallel with each other in the lateral direction, and a dielectric layer provided for covering the sustaining electrodes. The rear substrate has a plurality of ribs parallelly disposed in the vertical direction perpendicular to the sustaining electrodes of the front substrate for dividing the discharge space, a plurality of address electrodes provided in spaces between the ribs, and fluorescent film provided for covering the address electrodes.
In such a PDP, the dielectric layer and the ribs are formed by printing and baking glass paste. During baking of the glass paste, the baking temperature exceeds the distortion temperature of the glass. Thus, the dimension of the glass varies in accordance with thermal expansion and contraction. Therefore, when the substrates are secured to each other, it is difficult to accurately position the substrates. In particular, the deflection of both substrates is large in a peripheral region of the PDP.
FIG. 8 shows a matrix display of a conventional PDP. A pair of sustaining electrodes 1 and 2 are disposed in parallel with each other in a unit luminous region 3 of a discharge space defined by ribs 4. In such an arrangement, if the electrodes 1 and 2 deflect as shown by the dot-dash lines, the effective area of the luminous region does not change. Thus, the positioning of front and rear substrates can be easily and accurately performed. However, there are disadvantages in that luminous efficacy is reduced.
In order to increase the luminous efficacy, it is possible to form a projection on a side of the electrode. However, the projection gives rise to another problem.
FIG. 9 shows an example of projections 5 formed on a side of each electrode so as to oppose each other. By providing the projections, luminous efficacy and luminance are increased. However, if the electrodes 1 and 2 deflect as shown in the figure, a part of the projection 5 may be hidden by the rib 4. As a result, the area of the luminous region is reduced, so that discharge does not occur at the region or error discharge may occur.